Arctic amplification, the Jet stream and Extreme weather in Northern Hemisphere

A series of major extreme weather events in the Northern hemisphere including the heatwave in the United States in 2011, the Russian heatwave of 2010, the Pakistani floods of 2010 have now been attributed to a common physical cause. The scientists suggest in a new scientific study that man-made climate change repeatedly disturbs the patterns of atmospheric flow - the atmospheric Rossby waves of the jet stream - around the globe's Northern hemisphere through a subtle resonance mechanism.

"An important part of the global air motion in the mid-latitudes of the Earth normally takes the form of waves wandering around the planet, oscillating between the tropical and the Arctic regions. So when they swing up, these waves suck warm air from the tropics to Europe, Russia, or the US, and when they swing down, they do the same thing with cold air from the Arctic," explains lead author Vladimir Petoukhov.

"What we found is that during several recent extreme weather events these planetary waves almost freeze in their tracks for weeks. So instead of bringing in cool air after having brought warm air in before, the heat just stays. In fact, we observe a strong amplification of the usually weak, slowly moving component of these waves," says Petoukhov.

Australian Heatwave part of global warming trend says IPCC head Pachauri

The IPCC chairperson is visiting Australia and commented that the Extreme heatwave and catastrophic bushfires that Australia is experiencing is an 'unmistakeable' part of a global trend of an increase in the frequency and intensity of heatwaves and other extreme weather events. Indeed, researchers from the Potsdam Institute for Climate Impact Research (PIK) have just released a new study - Global increase in record-breaking monthly-mean temperatures - which clearly shows the present Australian heatwave records being broken and the US recording it's hottest year in 2012, are both part of this global trend.

Sea Level rising 60% faster than IPCC projections

Sea Level is rising 60% faster than IPCC projections according to a new climate change related study comparing the actual rise in CO2 concentration, global temperature and sea level with past projections done by the IPCC.

Rising Global temperatures are consistent with past projections made by the IPCC fourth assessment report. But Projections for sea level rise amounted to 2 mm a year, while sea-levels are actually rising at a rate of 3.2 mm a year.

Lead author of the study, Stefan Rahmstorf, said: "This study shows once again that the IPCC is far from alarmist, but in fact has under-estimated the problem of climate change. That applies not just for sea-level rise, but also to extreme events and the Arctic sea-ice loss."

Figure 2: Sea level measured by satellite altimeter (red with linear trend line; AVISO data from (Centre National d'Etudes Spatiales) and reconstructed from tide gauges (orange, monthly data from Church and White (2011)). Tide gauge data were aligned to give the same mean during 1993–2010 as the altimeter data. The scenarios of the IPCC are again shown in blue (third assessment) and green (fourth assessment); the former have been published starting in the year 1990 and the latter from 2000. From Comparing climate projections to observations up to 2011 Stefan Rahmstorf et al 2012 Environ. Res. Lett. 7 044035 doi:10.1088/1748-9326/7/4/044035

Climate meltdown: Global Warming heading towards 6 degrees C warns World Bank

Last night I sat down and skimmed through the 106pp report prepared by the prestiguous Postdam Institute for Climate Impact Research (PIK) for the World Bank. It is a shocking read, that we are presently on the business as usual emissions path of 4 degrees C of global warming by about the 2060s and 6 degrees C of warming by the turn of the century, just 88 years hence.

The United Nations Environment Program warns that Greenhouse Gas Emissions Gap Widening as Nations Head to Crucial Climate Talks in Doha. The International Energy Agency warned in their 2011 World Energy Outlook report that we are on a 4-6 degree Celsius trajectory and that 80 percent of carbon emissions infrastructure has already been built and is in operation. We cannot afford to add any new carbon intensive infrastructure that will continue to pollute for 30-50 years, yet the World Resources Institute reveals nearly 1,200 Proposed Coal-Fired Power Plants, the majority in India and China.

But grassroots action is having an impact: thousands rallied against coal across India, and a very first Arab Day of Climate Action (Photos) organised by the Arab Youth Climate Movement occurred on November 10. In the US, the Sierra Club reports victories in stopping the coal rush.

A recent Price WaterhouseCoopers report warned that Business as usual Carbon emissions heading towards 6°C (10.8°F) of global warming this century. So there is widespread agreement from science and scientists, energy experts and experts in global economics and accounting that we are facing a climate meltdown.

Related: 4 Degrees or More? Climate Change: The Critical Decade - a speech by Professor Hans Joachim Schellnhuber, Director of PIK. The article includes a CSIRO media release on +4ºC scenarios for Australia's future climate. | Another view from Systemic Disorder: World Bank’s call for slowing global warming ignores own role

Indian monsoon more likely to fail as global warming accelerates - Climate tipping point

A new predictive study for future monsoon failure in India says that full season failure will become much more likely in the next two hundred years. Failure of the Indian Seasonal Monsoon (ISM) has been identified as a climate change tipping point by climate scientists.

The study highlighted that monsoon rains could fail about one year in every five between 2150 and 2200 with continued global warming due to continued human burning of fossil fuels, and related shifts in tropical air flows.

More than a billion people are dependent on the reliability of the Indian summer monsoon (ISM) for agricultural productivity. A small variability in rainfall on the Indian sub-continent has large impacts on agriculture. Lower rainfall can reduce crop yield, while excessive rain causes flooding damaging to crops and disruption to peoples' lives. India's monsoon lasts from June to September each year.

Global Warming threshold for Greenland Ice Sheet collapse reduced to 1.6 degrees C

New research from the Potsdam Institute for Climate Impact Research and Universidad Complutense de Madrid has lowered the best estimate for the irreversible collapse of the Greenland Ice Sheet down to 1.6 °C, making the ice sheet more vulnerable than previously thought to global warming. The previous best estimate was 3.1 °C. As we currently have 0.8 °C of global warming, by the middle of the century we could easily pass this new threshold unleashing an ultimate sea level rise of several metres.

Already we have seen record summer melting in Greenland in 2010, and near record mass loss in 2011. According to NOAA the melt season in 2011 lasted up to 30 days longer than average and it affected 31 percent of the ice sheet surface, making 2011 one of just three years since 1979 where melt area exceeded 30 percent. Polar regions are warming much faster and to a greater degree than any other latitude on earth.